Clinical predictors and microbiology of ventilator-associated pneumonia in the intensive care unit: a retrospective analysis in six Italian hospitals

Abstract

The purpose of this study was to assess the main clinical predictors and microbiological features of ventilator-associated pneumonia (VAP) in the Intensive Care Unit (ICU) environment. This work is a retrospective analysis over one year from September 2010 to September 2011. Patients' risk factors, causes of admission, comorbidities and respiratory specimens collected in six Italian ICUs were reviewed. Incidence and case fatality rate of VAP were evaluated. After stratification for VAP development, univariate and multivariate analyses were performed to assess the impact of patients' conditions on the onset of this infection. A total of 1,647 ICU patients (pts) were considered. Overall, 115 patients (6.9 %) experienced at least one episode of VAP. The incidence rate for VAP was 5.82/1,000 pts-days, with a case fatality rate of 44.3 %. Multivariate analysis showed that admission for neurological disorders (aIRR 4.12, CI 1.24-13.68, p = 0.02) and emergency referral to ICU from other hospitals (aIRR 2.11, CI 1.03-4.31, p = 0.04) were associated with higher risk of VAP, whereas a tendency to a higher risk of infection was detected for admission due to respiratory disease, cardiac disease, trauma and for having obesity or renal failure. A total of 372 microbiological isolates from respiratory specimens were collected in VAP patients. The most common species were Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa, showing high resistance rates to carbapenems. Neurological disorders and emergency referral at the admission into the ICU are significantly associated with the onset of VAP. A high incidence of multi-drug resistant Gram- species was detected in the respiratory specimens.

Resistance Trends and Treatment Options in Gram-Negative Ventilator-Associated Pneumonia

“…European clinical studies also support the prominent role of P. aeruginosa in VAP (14–19% of cases) [32, 33]. …”

Microbial cause of ICU-acquired pneumonia: hospital-acquired pneumonia versus ventilator-associated pneumonia

“…The emergence of infections caused by carbapenem-resistant Enterobacteriaceae (CRE) worldwide represents an alarming problem, although the prevalence of such infections is highly variable across different countries [25][26][27]. No studies specifically addressing the role of CRE in HAP and VAP are available so far.…”

How Should We Treat HAP/VAP Caused by Carbapenemase-Producing Enterobacteriaceae?

“…[5][6][7] In this setting, the emergence of infections caused by carbapenem-resistant Enterobacteriaceae (CRE) represent an alarming problem due to the lack of available therapeutic options, leading to inadequate antibiotic treatment and increased mortality. 8,9 Limited data regarding the optimal antimicrobial regimen for the treatment of HAP/VAP due to CRE are available. Based on recent data, carbapenems might probably play a pivotal role also when the isolate displays a resistant phenotype, but attention must be paid to dose, modality of administration (extended infusion) and plasma drug levels.…”